Big Rock Solar Farm

OperatingBESS

Ranked #24 of 194 BESS plants in CA#219 of 963 nationally

200 MW BESS operating in Imperial, CA — California Independent System Operator

EIA

200 MW

Nameplate Capacity

Generators

unit

Batteries

Technology

2025

Operating Since

Location

Coordinates

32.7334, -115.7137

County

Imperial, CA

Nearby Plants

CED West Side Canal Battery Storage
BESS131 MW · 0.6 km
Kingsley Solar Farm
BESS299 MW · 2.2 km
Campo Verde Solar
Solar147.4 MW · 2.5 km

Status

Project statusOperationalSolar Power World · 2025-09-04

Latest milestoneCOD achieved · 2024-09-04Calexico Chronicle · 2025-09-04

Ownership & Operator

Field	EIA	GEM	Wikidata
Operator	Big Rock ESS Assets, LLC	—	—
Owner(s)	Big Rock ESS Assets, LLC	—	—
Status	Operating	—	—

Ownership Chain

No GEM tracker match for this plant — ownership chain unavailable.

DeveloperGore Street Energy Storage Fund±Calexico Chronicle · 2025-09-04

About

Big Rock Solar Farm is a 200 MW battery energy storage system (BESS) located in Imperial County, California. The facility, owned and operated by Big Rock ESS Assets, LLC, commenced operations in 2025. It consists of a single generator utilizing batteries as its primary fuel source, with a storage duration of one hour.

The plant operates within the California Independent System Operator (CAISO) balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. Big Rock Solar Farm ranks as the 63rd largest energy storage facility in California out of 112, and 311th nationally out of 514.

Generated from EIA, GEM, and public data sources

EIA Plant Profile

Engineering & Generators

Grid Context

ISO/RTO

CAISO

Market

ISO/RTO Member

NERC Region

WECC — Western Electricity Coordinating Council

Balancing Authority

Regulatory

AgencyImperial County Board of SupervisorsThe Desert Review · 2026-02-12

Latest rulingApprovalThe Desert Review · 2026-02-12

Generation

−2.0K MWh

Net Charging

-14.6K MWh

Annual Net Energy

-1.2%

Capacity Factor

Positive values indicate net discharge (generation exceeds station load). Negative values indicate net charging. Pure battery storage plants are typically net negative due to round-trip efficiency losses.

Financial Data

EIA Avg CostEIA Construction Cost AveragesMEDIUM

2023

Construction CostOperating CostPricing & Revenue

$1,361/kW

Est. Construction Cost

Total estimated cost: $272.2M

Technology Average·Based on EIA averages — not plant-specific financial reports

Pricing & Market Data

HIGH confidence

Market Position

ISO/RTO Market